Australian Toadlets and Water Frogs: Myobatrachidae - Behavior And Reproduction

eggs species female stomach

Most of the frogs in this family hide themselves away during the day. Some stay under damp leaves, moss, logs, or rocks on the ground, and others burrow. Burrowers may use their front legs to dig head first, or they may use their hind legs to scramble into the ground back end first. The turtle frog, which has a body with the shape of a turtle but without the shell, is a head-first burrower. It uses its short, but thick and strong front legs to scrape aside the sand and pushes its hard snout forward. A few species, such as Eungella torrent frog, may be active day or night. Some species that stay above ground for much of the year will burrow during the dry season and only return to the surface after the rainy weather returns.

In the breeding season, the males of some species set up and defend territories. For instance, male stonemason toadlets will get into wrestling matches over a good calling place. In other species, such as the quacking froglet, the males do not set up territories and instead chase after females. As many as five males may try to mate with a single female at the same time.

Most of the frogs in this family mate only at certain times of the year. For those that live in areas with dry and rainy seasons, the mating period usually happens in the rainy time of year. Usually, the males call only or mainly during the breeding season, although the males of some species call almost year-round. Different species have different calls. For instance, the smooth toadlet makes a buzzy, creaking sound, the eastern sign-bearing froglet gives a loud "eeek," and the Victorian smooth froglet has a repeating call that starts with a short quacking noise and follows with a repeated "tik-tik-tik-tik-tik-tik-tik." Most males call only at night, but those species that are active during the day also call sometimes in broad daylight. The moss frog, for example, makes its knocking call in the daytime from a hiding spot among plants on the floor of its mountain rainforests. Depending on the species, the males may call from underground, from a stream, pond or other watering hole, or from a hiding place on land, as the moss frog does.

Usually, the males and females pair and mate at the calling site. To mate, the male must climb onto the female's back as she lays her eggs. In a few species, however, the male calls not from the watering hole where he will mate, but from land a distance away. When a female approaches him, he climbs onto her back and she carries him to the water. The floodplain toadlet does things a little differently. Instead of the male climbing onto the female's back, she squirms underneath him while he is calling. Once she is fully beneath him, he stops calling, holds onto her, and they move to the water to mate.

THAT'S A MOUTHFUL!

The female gastric brooding frog of Australia takes very good care of her young. After she lays up to two dozen eggs, she puts them in an especially safe place where they can develop and grow, and that place is inside her stomach. Normally, the stomach acids digest things that animals eat, but the acid in these frogs' bellies turns off so the eggs can safely turn into tadpoles and then froglets inside the female's stomach. When the froglets are finally born, they leave her body the same way they came in: through her mouth. Scientists had just begun studying these unusual animals for use in controlling stomach acid in humans when the frogs disappeared. One of the two gastric brooding frog species vanished in 1983, and the second species, which was just discovered in 1983, disappeared in 1985. The IUCN now considers both to be Extinct. The same method that the frog used to turn off its stomach acid is now used in medicines to help people who have stomach ulcers. An ulcer is a sore on the wall of the stomach.

The females of some of the species in this family, like the tinkling frog, mate in the water and lay their eggs there. Their eggs hatch into tadpoles that swim off in the water and eventually turn into froglets. Others, such as the red-backed toadlet, lay their eggs on land. When rains drench the land, the eggs hatch into tadpoles that float in the rainwater or squirm on the wet soil to get to a pond or other watering hole, where they eventually change into froglets. Moss frogs also lay their eggs on land, but their tadpoles survive without a pond or even a puddle. Moss frog eggs are large and coated with jelly. When the tadpoles are born, they live in the leftover jelly for more than a year, even surviving under a layer of winter snow. After about 13 months, they finally turn into froglets. Female sandhill frogs and a few other species lay their gel-covered eggs underground. These eggs hatch into froglets, skipping the tadpole stage.

Perhaps oddest of all are the hip pocket frogs and the gastric brooding frogs. Female hip pocket frogs lay their eggs in and/or under damp leaves on the ground. The female stays with her eggs until they are ready to hatch. The male then takes over. He rests the front part of his body on the hatching eggs, and up to a dozen newborn tadpoles squirm up the sides of his body and into his two pouches, one of which is on each hip. In about two months, froglets crawl out of the pockets to face the world. In the gastric brooding frogs, on the other hand, the female takes charge. After she lays her eggs, she swallows them. The eggs turn into tadpoles and then froglets in her stomach and leave her body through her mouth. While the eggs are in her stomach, she stops eating.

Citing this material

Please include a link to this page if you have found this material useful for research or writing a related article. Content on this website is from high-quality, licensed material originally published in print form. You can always be sure you're reading unbiased, factual, and accurate information.

Highlight the text below, right-click, and select “copy”. Paste the link into your website, email, or any other HTML document.